Welding apparatus



April 15, 1947- s. PITT ETAL 2,418,951

WELDING APPARATUS Filed June 29, 1944 5 Sheets-Sheet 1 Arron/Imc April15, 1947. s. PITT :TAL 2,418,951

WELDING APPARATUS Filed June 29, 1944 3 Sheets-Sheet 2 M /N VE N TORS22/ T B); D. lf. WA TERS QQ n Wim A TTORNEV April 15, 1947. s. PITT ETAL2,418,951 v WELDING APPARATUS /M/EA/rons S. P/ TT D. V WATERS e R n MLMATTORNEY Patented Apr. 15, 1947 WELDING APPARATUS Samuel Pitt,

Vtaters, Flemington, Electric Company,

5 Claims.

This invention relates to welding apparatus, and more particularly toapparatus for welding grid structures for vacuum tubes.

In certain types of grid structures i'er vacuum tubes, the grid wiresare spirally wound on a mandrel including supports, such as longitudinalwires', to which the convolutions of the grid wire are to be secured bywelding.

An object of the invention is to provide a welding apparatus which issimple in structure and highly eiiicient for the welding of grids.

With this and other objects in view, the invention comprises a weldingapparatus having a support for a mandrel, upon which a supporting memberis disposed longitudinally thereof and a wire wrapped spirally thereon,to serve as an electrode, a movable electrode mounted for movementlongitudinally of the mandrel to cause welding of the convolutions ofthe wire to the support, and means to feed an inflammable material tothe wires in advance of the movable electrode.

Other objects and advantages will be apparent from the followingdetailed description when con-- sidered in conjunction with theaccompanying drawings, wherein Fig. l is a top plan View of the weldingapparatus;

Fig. 2 is a Vertical sectional view taken substantially along the line2-2 of Fig. l;

Fig. 3 is a fragmentary sectional View taken along the line 3--3 of Fig.2;

Fig. 4 is a fragmentary front elevational view taken along the line 4-4of Fig. l;

Fig. 5 is a fragmentary front elevational View taken along the line 5-5of Fig. 2;

Fig. 6 is a fragmentary sectional view taken along the line 6--6 of Fig.2;

Fig. 'l is an enlarged vertical sectional view of a portion of theapparatus, and

Fig. 8 is an enlarged fragmentary detail view of one of the controlcams, this View being taken along the line 8-8 of Fig. 1.

Referring now to the drawing, the apparatus is mounted upon a suitablesupport such as a bench I and has a base II of a suitable insulatingmaterial. A copper plate I2 extends the full width of the base I I andis fixed thereto, as at I4, adjacent the ends thereof. The base II iscut away, as at I5, to receive busbars IS and Il, the former extendingvertically through an aperture I8 in the bench IU and having a lateralportion I9 fixed to the copper plate I2, as illustrated in Fig. 2. Thebus-bar I'I extends through an aperture 2l) in the bench IU and throughthe cutaway portion I of the hase Ii. The part of Westfield,

and Daniel Vaughn N. J., assignors to Western Incorporated, New York, N.Y., a corporation of New York Application June 29, 1944, Serial No.542,668

the cutaway portion indicated at ZI extends longitudinally of the baseII in the form of a slot with the aperture 2E), which may also be termedan elongate slot, for the movement of the busbar Il with its movableelectrode as will hereinafter be described. The bus-bars It and il areelectrically connected to the secondary winding of a transformer 22 of awelding circuit as illustrated in Fig. 2. An insulating strip 23 extendsthe full length of the slot 2i to serve as a shield between the bus-barIl and the copper plate l.

The copper plate I2 carries sets of pins 25 at selected positions forsupporting elements of the contour illustrated in Figs. 2 and 7. Thesupporting elements 25 have base portions El apertured at 2S to receivethe pins 25 and also have V-grooves 29 in their upper surfaces toreceive the reduced ends 30 of a mandrel 3l. The manm drel 3l in thepresent embodiment is of the size illustrated in Figs. 1 and 2 but maybe oi varied lengths and/or diameter, depending upon those required forthe grid structures to be welded. To compensate for the variation in thelength oi the mandrels, the supporting elements 2li may be disposed atvaried positions upon the copper plate i2 through the aid of the pins25. In the present illustration the mandrel 3| is .formed of coppercylindrical in general contour, with its reduced ends adapted to restand be centrally aligned in the V-grooves 29. Recesses 32 are formed inthe periphery of the mandrel at spaced positions as illustrated in Fig.7, to receive supports or mounting wires 33 which are to be welded tothe convolutions of a spirally wound grid wire 3d.

A frame 35 of the cross-sectional contour illustrated in Fig. 2 andextending the full length o the base I I, is mounted thereon and formedto receive a carriage 31. Sets of rollers 3S of the carriage 31 arepositioned to ride upon tracks beneath guides 40, while a set of rollers4i, positioned to ride in a longitudinal groove i2 of the frame 35i,cooperates with the rollers 3S to condition the carriage forlongitudinal movement in a given path parallel with the center line ofthe mandrel 3i.

Diagonal members 45, spaced from each other as illustrated in Fig. 1 andintegral with the carriage 3l, straddle a housing 45 at their upper endsand are iixed thereto by suitable means such as welding. The housing #lhas a shank il movably disposed therein and normally urged downwardlythrough the force of a spring fill. The force of the spring 48 may bevaried through the aid of a thumb screw 49, the latter being threadedlydisposed in the housing and normally held in any desired adjustedposition through the aid of a retaining spring 5G. The shank 4l carriesa pin 52 which extends laterally through the shank and through elongateapertures 53 in the sides of the housing 46. Cams 54, pivotallysupported as at (Figs. 2 and 3), are adapted, through the aid of aU-shaped handle 5l', connecting both of the cams for simultaneousmovenient, to move the shank 41 through the aid of the pin 52 into theupward position as illustrated in Fig. 2. A yoke 69 is carried by theshank 4l' and in turn carries a roller electrode Ei through the aid of aremovable pin 52. The bus-bar l1 is xed to the yoke and in this mannerthe roller electrode 6| is included in the welding circuit.

A tank or receptacle 55, disposed between the diagonal members 45 of thecarriage Si, rests upon a lateral support 6G and is secured thereto. Acover 6l' normally closes the receptacle E5 and permits access thereto.An inflammable material such as a mixture of alcohol and water,indicated at 63, is disposed in the receptacle and is adapted to be fedto the mandrel through the aid of nozzles 69 and 'iii controlled byvalves 'il and T2. The valves 'Il and 'f2 are of the commercially knowntype, adjustable to allow small quantities of the liquid to pass throughnozzles and onto the mandrel. Through the aid oi cam levers 'IS and 11i,the valves may be closed against the passage of the liquid to thenozzle.

The means for moving the carriage S7 reciprocally between given limitsincludes a threaded shaft TS, which is driven by a reversible motor il'through the aid of a belt and pulley connection '18. The ends or" theshaft 75 are journalled in suitable bearings 19 and 8G in end plates 8land 8'. of the housing 36. The connection between the shaft 'l5 and thecarriage 3l is brought about through the aid of a threaded element B3 ofthe contour illustrated in Fig. 2. The element 83 extends through anaperture 84 in the carriage for movement into operative engagement withthe shaft, as indicated in dot and dash lines, or out of operativeengagement with the shaft as indicated in solid lines in this figure.The element is pivotally supported, at 85, for movement with thecarriage and for movement about the pivot through the aid of a handle8l' or a cam controlled arm 85. The arm 38 carr'es a cam roller 89positioned to ride upon either one of the control cams SQ 0r Sl. Thecontour of the control cam 9! is illustrated in Fig. 8 and the contourof the cam 95 is identical therewith but is disposed in a reverse orderso that the diagonal portions of the cams, as indicated at S2, face eachother. The cams 9) and Si are mounted upon the adjacent cover member tand are disposed in the path of the roller S9. A unit $5, shown indetail in Fig. 6, includes an aperture .'55 through which the arm 88extends and a spring pressed plunger 9i adapted to be actuated by thearm and to hold the arm with the element 33 in operative or inoperativepositions.

Considering now the operation of the apparatus, let it be assumed thatthe grid wire 34 has been wound upon the mandrel 'Jl over the supports33 and that this assembly is disposed in the position illustrated, withthe reduced ends 39 of the mandrel resting in the supporting elements26. r:Che mandrel, therefore, will serve as an electrode in the weldingcircuit, it being formed of copper or other suitable conductive materialresting in the copper elements 2B, which in turn are disposed upon thecopper plate l2 to which the bus-bar I6 is fixed. With the carriage atCil one of the starting positions, for example, as illustrated in Fig. lat the extreme right, the roller electrode fil may be lowered under theforce of the spring 4S by the movement of the handle 57 from the solidline position (Fig. 2) to the dot dash line position, allowing thespring to -force the electrode 6i into intimate engagement with the gridstructure adjacent one of the supports 33, as illustrated in Fig. 7. Thelever 'I3 of the valve ll will then be moved into its vertical or openposition to allow the inflammable mateto be through the nozzle 59 andonto the grid structure in advance of the electrode 6I. The motor il maythen be energized to cause the to rotate in a given direction, and uponmovement of the element 83 into its operative position through the aidoi the handle 87 after the cam roller has been moved free of its camSSG, the carriage be moved at a predetermined to t.-e left. During thismovement of the carriage the electrode Si rides o-ver the convoluol thegrid wire 34 and causes welding of these eonvolutions to the adjacentsupport 33. By the feeding of the inflammable material B8 to theportions to be welded in advance of the welding operation or electrode6I, this material is ignited, causing a iash to burn away the oxygen andto remove any oxidized coatings on the grid wire support so as to assurea satisfactory weld. This operation continues until the carriage reachesthe end of its travel controlled by the operator er by the cam Si. If bythe latter, the carriage will stop its movement to the left by the canirolle` S the n "S i movnrf the At this time means may be included toopen the welding circuit if desired, and to also rev e the direction ofthe motor il. During this ii-.. operation the convolutions of the gridwires 34 were welded to one of the supports The mandrel may then beturned to present another support S3 t0 the welding position, and uponthe retu movement of the carriage the convolutions oi the grid wire willbe we ded thereto. During this return movement the valve 1| is closedand the valve T2 opened through the movement o its lever N into thevertical position, so that the inilammable material will be fed to thegrid structure in advance of the electrode rhis operation is repeateduntil all four of the supports 33 have been welded to the adjacentconvolutions of the grid wire, after which this mandrel with thecomplete grid structure thereon may be removed from the apparatus andanother disposed in its place.

Although specific improvements of the invention have been shown anddescribed, it will be understood that they are but illustrative and thatvarious modifications may be made therein without departing from thescope and spirit of this invention as deined by the appended claims.

What is claimed is:

l. A welding apparatus comprising a support for an article to be welded,an electrode, means to include the electrode and the support in awelding circuit, a carriage for the electrode, reversible power means,an element supported by the carriage to connect the carriage with thepower means to thereby cause reciprocation of the electrode, and meansdisposed adjacent the path of the carriage to cause movement of theelement of operative engagement with the power means to limit thedistances the carriage and electrode will travel in both directions.

mit

2. A welding apparatus comprising a support for an article to be welded,an electrode, means to include the electrode and the support in awelding circuit, a carriage for the electrode, reversible power means,means to yconnect the carriage thereto to thereby cause reciprocation ofthe electrode to weld different portions of the articles during thereciprocal movement of the electrode, and separate means movable withthe carriage upon their respective sides of the electrode to selectivelyapply an inflammable mate rial to the article in advance of theelectrode, to cause burning of an oxide coating on the article inadvance of the welding operation.

3. A welding apparatus comprising a support for an article to be welded,an electrode, means to include the electrode and the support in awelding circuit, a carriage for the electrode, rollers for supportingthe carriage and tracks therefor to guide the carriage for reciprocablemovement relative to the article, spaced guides parallel with thearticle, and a member supported by the carriage and movable between theguides to maintain the carriage in a, fixed path parallel with thearticle.

4. A welding apparatus comprising a support for an article to be welded,an electrode, means to include the electrode and the support in aWelding circuit, a carriage for the electrode, ren versible power means,an element supported by the carriage to connect the carriage with thepower means to thereby cause reciprocation of the electrode, an armlcarried by the element, means to actuate the arm to move the elementout of operative engagement with the power means to limit the distancesthe carriage and electrode vvll travel, and means to engage the arm whenactuated to cause it to hold the element in its inoperative position.

5. A welding apparatus comprising a support for an article to be welded,an electrode, means to include the electrode and the support in awelding circuit, a carriage for the electrode, reversible power means,an element supported by the carriage to connect the carriage with thepower means to thereby cause reciprocation of the electrode, an armcarried by the element, means to actuate the arm to move the element outof operative engagement with the power means to limit the distances thecarriage and electrodewill travel, and a, unit operable through the armto selectively hold the element in its operative and inoperativepositions.

SAMUEL PITT. DANIEL VAUGHN WATERS.

REFERENCES CITED The following references are of record in the le oithis patent:

UNITED STATES PATENTS Number Name Date 1,365,015 Zwicker Jan. 11, 19211,610,616 Schlaf Dec, 14, 1926 1,738,465 Wagner et al Dec. 3, 19292,163,590 Ganahl et al June 27, 1939 2,284,851 Tiedemann June 2, 19421,680,233 Townsend Aug, 7, 1928 2,033,851 Roth 1- Mar. 10, 19361,115,943 Knipe Nov. 3, 1914 1,452,936 Schuman Apr. 29, 1923 2,040,349Wagner (2) May 12, 1936 2,071,418 McBerty Feb. 23, 1931 2,367,715Chapman Jan. 23, 1.945

